Polarized electric signal-bell.



PATENTED MAR. 12, 1907.

w. M. THOMAS. POLARIZEDBLEGTRIG SIGNAL BELL.

LPPLQIOATIDN FILED AUG. 3, 1906.

2 SHEETS-SHEET 1.

BATENTBD MAR. 12, 1901 w. M. THOMQS, 1

2 sinus-SHEET a.

APPLIOATION FILED AUG, 3, 1906- nwemrib UNITED; STATES PATENT OFFlGE.

WILLIAM M. THOMAS, F onIoAeo, ILLINOIS, ASSlGNQR or ONE-HALF r0 orronIsnNscIrIML, or CHICAGO, ILLINOIS.

POLARlZED- ELECTRIC SIGNAL-BELL.

To all whom it may concern:

Beit known that I, WILLIAM M. THOMAS, a citizen of the United States,residing at a Chicago, in the county of Cook and State of cheap toconstruct, ornamental in apperance, and so arranged and constructed asto be substantially bug-proof.

Other objects of my invention will become apparent to those skilled inthe art from the following description, taken in conjunction with theaccompanying drawings.

In the drawings, Figural is a plan View of my bell, showing art of thegong broken away, revealing t e internal mechanism. Fig. 2 is a sectiontaken on line 22 of Fig.v 1. Fig. 3 is a section taken on line 33 ofFig. 1. Fig. 1 is an end view of the electromagnet and its support.

In all of the views the same numerals of reference indicate similarparts. i

' In the drawings, 5 is a base-plate, which i may he of insulatingmaterial, as shown in I the drawings, or it may be of metal with the Zbinding-posts 6 6 properly insulated therefrom. The binding-posts 6 and6 are the terminals of the coils 7 and 7 and 7 are shown connectcdinseries and in the proper direction w th reference to each other, for thepurpose of causing the responsive armature thereof to respond toalternating impulses of electric current that may be sent through them.

8 is the core of. the electromagnet provided with terminal pole-pieces 9and 9, the latter being shown'more plainly in Hg. {1. A support 10,which may be of any desired material-such as brass, iron, or the like-islocated, with reference to the core 8 and its respective pole-pieces,midway between the said pole-pieces, the core 8 fitting snugly in aperforation made through said support. The support 10 is perforated fromits top surface to receive the threaded stem 11 for the purpose ofsecuring the gong 12 in place thereon.

said gong being held in position by reason of Specification of LettersPatent. Application filed August 3,1906. Ser a No 329.018-

The coils 7 Q Patented March 12,1907.

I its threaded engagement with the threaded stem 11 and'by means of thenut 13.. The gong may be vertically adjusted by the means employed forits support. I

Screws 14 and. 1'4 pass through the base 5 into threaded perforationsmade in the legs 15 '15 of the support 10. Pointed pivotal screws 16 16take through threaded perfora- 3 tions made in the legs 15 15 and formapiv- 1 etc]. axis upon which the armature 17 is adapted to be vibrated.The armature 17 is preferably made of ether of steel hardened andermanently ma netized when it is denating impulses of electricity.Hammers opposite pole-piece. When an impulse of electricity is sent inthe opposite direction to that of the first-named impulse, the endof thearmature that was previously repelled will he attracted and the otherend will be repelled, so that impulses of electricity at frequentintervals and passing through the coils in respective oppositedirections will serve to vibrate the armatureand cause the hammers orclappers 19 and 19 to alternately strike cause the gong to soundforcausing the desired alarm. Y

The bell may be placedin any position on the walls or the ceiling or inany desirable situation without materially affecting the operationthereof. j

While l have shown and described only a single embodiment of myinvention, it is apthe under side of the gong 12, and thereby i madetherefrom without dcpartipg from the spirit and scope thereof. j llaving thus described. my invention, what l claim, and desire to secureby Letters Pat- 'ent of the Lnitcd States, isp l. A signal-lz0llcomprising a base, a hori- ZUlll'ttllIY-(llS'POHt-ll clcctromagnct-cnre,hav- 18 and 18, adapted tostrikethe under edge parent that considerablevariation may b8 sirab e to use the bell for response to alter- Oneendof the arma- 9 and theother end will be attracted by the v ingdownwmdly-projeciing poles, a support, carrying said core locatedintermediate vthe poles thereof, a 'st em vertically rojectin from saidsu 'murt; a gong adjustabyeecure to said stem, and 2m armature centrallypivoted to said support, the ends whereof con- 5 front the mics of saidimwnet. I a

2. In combination, a nmgnet-eore having projecting ole-pieces, acentrally-located tl'ian ular su ))01't hav 1"" le' s for attach- PJ Dment to :1 base, an armam'lre pivoted to said 'f support piviet-siudehiking throu 11 said

